1. Technical Field
The present invention relates to changing the ambient air temperature inside a structure and, more specifically, to a cooling method and apparatus which provides a simple, yet very energy-efficient, means of cooling the interior of a structure and the water in a water storage unit.
2. Background Art
Human beings are known for their ability to adapt to their environment or, to adapt their environment to them. One example of this quality is the continued expansion of human populations into areas previously deemed inhospitable to human life. Desert communities such as Phoenix, Ariz. and Las Vegas, Nev. are two well-known and rapidly growing areas which support burgeoning populations. In order to survive in these hot, desert climates, most structures designed for human occupation are provided with one or more systems for cooling the air inside the structure. Some of the various types of systems used to cool the air inside a structure are typically rated by using a system which assigns a Seasonal Energy Efficiency Ratio (SEER) rating or number to the system. A higher SEER rating indicates a more efficient system when compared with a system having a lower SEER rating.
One popular method of cooling the air inside a structure that has been adopted in many hot climates is the evaporative cooler. Evaporative coolers use a simple combination of a water pump, absorbent cooling pads, and a fan to provide cool air. Using basic principles of gravity and evaporation, air is cooled by forcing it through the evaporative cooler. Water is pumped into water-retaining pads which line the interior surface of the evaporative cooler and the outside air is drawn into the evaporative cooler by a large blower fan. By drawing the outside air through the water-soaked cooling pads, heat is transferred from the air to the water as water evaporation (heat of vaporization) occurs and the cooled air is blown into the structure, thereby cooling the interior of the structure.
While generally effective, evaporative coolers have certain well-known limitations. For example, as the outside air temperature increases, the evaporation process cannot sufficiently lower the temperature of the air in a structure to provide an acceptable temperature for human occupation. The evaporation rate, however, will continue to increase as the temperature increases. In addition, in very humid climates, evaporative coolers can be ineffective for cooling occupied structures at even relatively low ambient air temperatures due to the high amount of water vapor in the air. Once the air is saturated with water vapor, no additional cooling can take place.
To overcome the limitations associated with evaporative coolers, people living in many desert climates have turned to refrigerated air-conditioning systems to cool the air inside a structure. Instead of using the principles of evaporation, traditional refrigerated air-conditioning systems use the properties of refrigerant gases such as freon to cool the temperature of the air.
While very effective, refrigerated air-conditioning systems suffer from several undesirable characteristics. Foremost, these systems are relatively expensive to operate when compared to the nominal operational costs associated with most evaporative coolers. During the hottest part of the summer in more severe desert climates, the cooling costs associated with supplying electricity for a refrigerated air-conditioning system for even modest-sized homes can become exorbitant. Secondly, the compressors, fans, and motors used in typical residential air-conditioning systems are very loud and can contribute to a high level of ambient noise in some residential areas. In addition, the size and shape of the various components of the refrigerated air-conditioning system makes them somewhat unsightly next to a residence. Finally, the continued growth in the use of air-conditioning systems requires an ever-increasing expenditure of precious resources to generate the electricity necessary to operate the systems.
In some areas of the country, evaporative coolers and refrigerated air conditioning systems are both used, during different parts of the season, to cool the air inside a structure. In a typical scenario, an evaporative cooler may be used to reduce the ambient air temperature inside a structure during the relatively cooler and drier spring and early summer months (i.e., April, May, and June). Then, once the outside ambient air temperature and/or humidity has exceeded the capabilities of the evaporative cooler, typically in July, August, and possibly September, the evaporative cooler is switched off and the refrigerated air-conditioning system is used to reduce the ambient air temperature. Towards the end of the summer months as the fall season arrives, temperatures and humidity levels drop, and the evaporative cooler may once again be adequate to provide the desired cooling effect. While the use of both systems is more efficient than either system alone, these hybrid systems still suffer from the deficiencies associated with the respective component systems described above.
What is needed, therefore, is an apparatus and method for more efficiently cooling the interior of structures, particularly in hot desert climates where refrigeration is the primary method of cooling, while simultaneously decreasing the overall consumption of electric power. Without developing more efficient methods for providing cool air in hot desert climates, operating expenses borne by consumers for refrigerated air-conditioning systems will continue to rise and our earth's natural resources will continue to be diminished at an overly excessive rate.